Add missing tests and doc for `IsSelfDualSemigroup` and friends#892

Merged

james-d-mitchell merged 3 commits intosemigroups:mainfrom james-d-mitchell:is-self-dual

Nov 15, 2022

+161-2

Commits on Nov 15, 2022

prop: add tests and doc for IsSelfDualSemigroup
james-d-mitchell
committed
semigrp: add tests for Reversed for fp semigroup elts
james-d-mitchell
committed
semifp: add tests and doc for AntiIsomorphismDualFpSemigroup
james-d-mitchell
committed